For recent ATP festivals we've been running Mixtape (or CD to be accurate!) Swap with attendees, all of which have been very successful, with hundreds of people taking part. Each time we do it we pick another concept; for example for one the tracklisting had to be an acrostic of your name, and for another it had to contain one track from each of the last 13 years (to celebrate Mogwai's return to headline ATP this Summer after they had originally headlined our first proper event back in 2000).
For the forthcoming End Of An Era ATP festivals at Camber Sands we will yet again be doing swaps with the following (optional!) very End Of An Era themed concepts picked by us from contributions by attendees:
Sam Page suggested: Songs To Play At The End Of The World
Andrew Parsons suggested: Favourite Final Tracks On Albums
We will announce a time and location for the mix swap at each event when we announce the full schedule of bands.